Francesco G. Mutti

Recent biocatalytic oxidation–reduction cascades

The combination of an oxidation and a reduction in a cascade allows performing transformations in a very economic and efficient fashion. The challenge is how to combine an oxidation with a reduction in one pot, either by running the two reactions simultaneously or in a stepwise fashion without isolation of intermediates. The broader availability of various redox enzymes nowadays has triggered the recent investigation of various oxidation–reduction cascades.

Redox Self-Sufficient Biocatalyst Network for the Amination of Primary Alcohols†

Driving the machinery: A biocatalytic redox-neutral cascade for the preparation of terminal primary amines from primary alcohols at the expense of ammonia has been established in a one-pot one-step method. Applying this artificial biocatalyst network, long-chain 1,ω-alkanediols were converted into diamines, which are building blocks for polymers, in up to 99 % conversion.

Introducing an In Situ Capping Strategy in Systems Biocatalysis To Access 6‐Aminohexanoic acid

The combination of two cofactor self-sufficient biocatalytic cascade modules allowed the successful transformation of cyclohexanol into the nylon-6 monomer 6-aminohexanoic acid at the expense of only oxygen and ammonia. A hitherto unprecedented carboxylic acid capping strategy was introduced to minimize the formation of the dead-end intermediate 6-hydroxyhexanoic acid. For this purpose, the precursor ε-caprolactone was converted in aqueous medium in the presence of methanol into the corresponding methyl ester instead of the acid. Hence, it was shown for the first time that esterases--specifically horse liver esterase--can perform the selective ring-opening of ε-caprolactone with a clear preference for methanol over water as the nucleophile.

Creating a Biocatalyst for the Production of an Optically Pure Sterically Hindered Amine

The preparation of optically pure amines is one of the current hot topics in asymmetric synthesis employing chemical methods or biocatalytic approaches. 3] The original route for the preparation of sitagliptin 1, a drug needed for the treatment of diabetes mellitus type 2, encompassed a metal-catalyzed asymmetric reduction of an enamine by a rhodium catalyst (Scheme 1). The metal-catalyzed asymmetric hydrogenation

Alkene Cleavage Catalysed by Heme and Nonheme Enzymes: Reaction Mechanisms and Biocatalytic Applications

The oxidative cleavage of alkenes is classically performed by chemical methods, although they display several drawbacks. Ozonolysis requires harsh conditions (−78°C, for a safe process) and reducing reagents in a molar amount, whereas the use of poisonous heavy metals such as Cr, Os, or Ru as catalysts is additionally plagued by low yield and selectivity. Conversely, heme and nonheme enzymes can catalyse the oxidative alkene cleavage at ambient temperature and atmospheric pressure in an aqueous buffer, showing excellent chemo- and regioselectivities in certain cases. This paper focuses on the alkene cleavage catalysed by iron cofactor-dependent enzymes encompassing the reaction mechanisms (in case where it is known) and the application of these enzymes in biocatalysis.